The instant invention is concerned with aryloxyacetic acids and pharmaceutically acceptable salts and prodrugs thereof which are useful as therapeutic compounds, particularly in the treatment of Type 2 diabetes mellitus, often referred to as non-insulin dependent diabetes (NIDDM), of conditions that are often associated with this disease, and of lipid disorders.
Diabetes refers to a disease process derived from multiple causative factors and characterized by elevated levels of plasma glucose or hyperglycemia in the fasting state or after administration of glucose during an oral glucose tolerance test. Persistent or uncontrolled hyperglycemia is associated with increased and premature morbidity and mortality. Often abnormal glucose homeostasis is associated both directly and indirectly with alterations of the lipid, lipoprotein and apolipoprotein metabolism and other metabolic and hemodynamic disease. Therefore patients with Type 2 diabetes mellitus are at especially increased risk of macrovascular and microvascular complications, including coronary heart disease, stroke, peripheral vascular disease, hypertension, nephropathy, neuropathy, and retinopathy. Therefore, therapeutical control of glucose homeostasis, lipid metabolism and hypertension are critically important in the clinical management and treatment of diabetes mellitus.
There are two generally recognized forms of diabetes. In type 1 diabetes, or insulin-dependent diabetes mellitus (IDDM), patients produce little or no insulin, the hormone which regulates glucose utilization. In type 2 diabetes, or noninsulin dependent diabetes mellitus (NIDDM), patients often have plasma insulin levels that are the same or even elevated compared to nondiabetic subjects; however, these patients have developed a resistance to the insulin stimulating effect on glucose and lipid metabolism in the main insulin-sensitive tissues, which are muscle, liver and adipose tissues, and the plasma insulin levels, while elevated, are insufficient to overcome the pronounced insulin resistance.
Insulin resistance is not primarily due to a diminished number of insulin receptors but to a post-insulin receptor binding defect that is not yet understood. This resistance to insulin responsiveness results in insufficient insulin activation of glucose uptake, oxidation and storage in muscle and inadequate insulin repression of lipolysis in adipose tissue and of glucose production and secretion in the liver.
The available treatments for type 2 diabetes, which have not changed substantially in many years, have recognized limitations. While physical exercise and reductions in dietary intake of calories will dramatically improve the diabetic condition, compliance with this treatment is very poor because of well-entrenched sedentary lifestyles and excess food consumption, especially of foods containing high amounts of saturated fat. Increasing the plasma level of insulin by administration of sulfonylureas (e.g. tolbutamide and glipizide), which stimulate the pancreatic xcex2-cells to secrete more insulin, and/or by injection of insulin after the response to sulfonylureas fails, will result in high enough insulin concentrations to stimulate the very insulin-resistant tissues. However, dangerously low levels of plasma glucose can result from these last two treatments, and increasing insulin resistance due to the even higher plasma insulin levels can occur. The biguanides increase insulin sensitivity resulting in some correction of hyperglycemia. However, the two biguanides, phenformin and metformin, can induce lactic acidosis and nausea/diarrhea, respectively.
The glitazones (i.e. 5-benzylthiazolidine-2,4-diones) are a more recently described class of compounds with potential for a novel mode of action in ameliorating many symptoms of type 2 diabetes. These agents substantially increase insulin sensitivity in muscle, liver and adipose tissue in several animal models of type 2 diabetes resulting in partial or complete correction of the elevated plasma levels of glucose without occurrence of hypoglycemia.
Disorders of lipid metabolism or dyslipidemias include various conditions characterized by abnormal concentrations of one or more lipids (i.e. cholesterol and triglycerides), and/or apolipoproteins (i.e., apolipoproteins A, B, C and E), and/or lipoproteins (i.e., the macromolecular complexes formed by the lipid and the apolipoprotein that allow lipids to circulate in blood, such as LDL, VLDL and IDL) . Cholesterol is mostly carried in Low Density Lipoproteins (LDL), and this component is commonly known as the xe2x80x9cbadxe2x80x9d cholesterol because it has been shown that elevations in LDL-cholesterol correlate closely to the risk of coronary heart disease. A smaller component of cholesterol is carried in the High Density Lipoproteins and is commonly known as the xe2x80x9cgoodxe2x80x9d cholesterol. In fact, it is known that the primary function of HDL is to accept cholesterol deposited in the arterial wall and to transport it back to the liver for disposal through the intestine. Although it is desirable to lower elevated levels of LDL cholesterol, it is also desirable to increase levels of HDL cholesterol. Generally, it has been found that increased levels of HDL are associated with lower risk for coronary heart disease (CHD). See, for example, Gordon, et al., Am. J. Med., 62, 707-714 (1977); Stampfer, et al., N. England J. Med., 325, 373-381 (1991); and Kannel, et al., Ann. Internal Med., 90, 85-91 (1979). An example of an HDL raising agent is nicotinic acid, a drug with limited utility because doses that achieve HDL raising are associated with undesirable effects, such as flushing.
Dyslipidemias were originally classified by Fredrickson according to the combination of alterations mentioned above. The Fredrickson classification includes 6 phenotypes (i.e., I, IIa, IIb, III, IV and V) with the most common being the isolated hypercholesterolemia (or type IIa) which is usually accompained by elevated concentrations of total and LDL cholesterol. The initial treatment for hypercholesterolemia is often to modify the diet to one low in fat and cholesterol, coupled with appropriate physical exercise, followed by drug therapy when LDL-lowering goals are not met by diet and exercise alone
A second common form of dyslipidemia is the mixed or combined hyperlipidemia or type IIb and III of the Fredrickson classification. This dyslipidemia is often prevalent in patients with type 2 diabetes, obesity and the metabolic syndrome. In this dyslipidemia there are modest elevations of LDL-cholesterol, accompanied by more pronounced elevations of small dense LDL-cholesterol particles, VLDL and/or IDL (i.e., triglyceride rich lipoproteins), and total triglycerides. In addition, concentrations of HDL are often low.
Peroxisome proliferators are a structurally diverse group of compounds that when administered to rodents elicit dramatic increases in the size and number of hepatic and renal peroxisomes, as well as concomitant increases in the capacity of peroxisomes to metabolize fatty acids via increased expression of the enzymes of the beta-oxidation cycle. Compounds of this group include but are not limited to the fibrate class of lipid modulating drugs, herbicides and phthalate plasticizers. Peroxisome proliferation is also triggered by dietary or physiological factors such as a high-fat diet and cold acclimatization.
Three sub-types of peroxisome proliferator activated receptor (PPAR) have been discovered and described; they are peroxisome proliferator activated receptor alpha (PPARxcex1), peroxisome proliferator activated receptor gamma (PPARxcex3) and peroxisome proliferator activated receptor delta (PPARxcex4). Identification of PPARxcex1, a member of the nuclear hormone receptor superfamily activated by peroxisome proliferators, has facilitated analysis of the mechanism by which peroxisome proliferators exert their pleiotropic effects. PPARxcex1 is activated by a number of medium and long-chain fatty acids, and it is involved in stimulating xcex2-oxidation of fatty acids. PPARxcex1 is also associated with the activity of fibrates and fatty acids in rodents and humans. Fibric acid derivatives such as clofibrate, fenofibrate, benzafibrate, ciprofibrate, beclofibrate and etofibrate, as well as gemfibrozil, each of which are PPARxcex1 ligands and/or activators, produce a substantial reduction in plasma triglycerides as well as some increase in HDL. The effects on LDL cholesterol are inconsistent and might depend upon the compound and/or the dyslipidemic phenotype. For these reasons, this class of compounds has been primarily used to treat hypertriglyceridemia (i.e, Fredrickson Type IV and V) and/or mixed hyperlipidemia.
The PPARxcex3 receptor subtypes are involved in activating the program of adipocyte differentiation and are not involved in stimulating peroxisome proliferation in the liver. There are two known protein isoforms of PPARxcex3:PPARxcex31 and PPARxcex32 which differ only in that PPARxcex32 contains an additional 28 amino acids present at the amino terminus. The DNA sequences for the human isotypes are described in Elbrecht, et al., BBRC 224;431-437 (1996). In mice, PPARxcex32 is expressed specifically in fat cells. Tontonoz et al., Cell 79: 1147-1156 (1994) provide evidence to show that one physiological role of PPARxcex32 is to induce adipocyte differentiation. As with other members of the nuclear hormone receptor superfamily, PPARxcex32 regulates the expression of genes through interaction with other proteins and binding to hormone response elements, for example in the 5xe2x80x2 flanking regions of responsive genes. An example of a PPARxcex32 responsive gene is the tissue-specific adipocyte P2 gene. Although peroxisome proliferators, including the fibrates and fatty acids, activate the transcriptional activity of PPAR""s, only prostaglandin J2 derivatives have been identified as potential natural ligands of the PPARxcex3 subtype, which also binds thiazolidinedione antidiabetic agents with high affinity.
The human nuclear receptor gene PPARxcex4 (hPPARxcex4) has been cloned from a human osteosarcoma cell cDNA library and is fully described in A. Schmidt et al., Molecular Endocrinology, 6:1634-1641 (1992). It should be noted that PPARxcex4 is also referred to in the literature as PPARxcex2 and as NUC1, and each of these names refers to the same receptor; in Schmidt et al. the receptor is referred to as NUC 1.
In WO96/01430, a human PPAR subtype, hNUC1B, is disclosed. The amino acid sequence of hNUC1B differs from human PPARxcex4 (referred to therein as hNUC1) by one amino acid, i.e., alanine at position 292. Based on in vivo experiments described therein, the authors suggest that hNUC1B protein represses hPPARxcex1 and thyroid hormone receptor protein activity.
It has been disclosed in WO97/28149 that agonists of PPARxcex4 are useful in raising HDL plasma levels. WO97/27857, 97/28115, 97/28137 and 97/27847 disclose compounds that are useful as antidiabetic, antiobesity, antiatherosclerosis and antihyperlipidemic agents, and which may exert their effect through activation of PPARs.
It is generally believed that glitazones exert their effects by binding to the peroxisome proliferator activated receptor (PPAR) family of receptors, controlling certain transcription elements having to do with the biological entities listed above. See Hulin et al., Current Pharm. Design (1996) 2, 85-102.
A number of glitazones that are PPAR agonists have been approved for use in the treatment of diabetes. These include troglitazone, rosiglitazone and pioglitazone, all of which are primarily or exclusively PPARxcex3 agonists. Many of the newer PPAR agonists that are currently under development or are in clinical trials have dual PPARxcex1 and xcex3 activity. These are expected to improve both insulin sensitivity and the lipid profile in patients having NIDDM.
Although glitazones are beneficial in the treatment of NIDDM, there have been some serious adverse events associated with the use of the compounds. The most serious of these has been liver toxicity, which has resulted in a number of deaths. The most serious problems have occurred using troglitazone. Because of the problems that have occurred with the glitazones, researchers in a number of laboratories have been investigating classes of PPAR agonists that are not glitazones and do not contain 1,3-thiazolidinedione moieties.
Compounds that are not glitazones but are agonists of PPAR sub-types are expected to be useful in the treatment of diabetes and associated conditions. PPARxcex1 agonists should improve the lipid profile and alleviate dyslipidemias by reducing elevated LDL levels and elevated triglyceride levels and/or increasing HDL levels. PPARxcex3 agonists should improve insulin sensitivity, reducing the need for insulin injections in patients with NIDDM. The role of PPARxcex4 is less well defined.
The class of compounds described herein is a new class of PPAR agonists that do not contain a 1,3-thiazolidinedione moiety and therefore are not glitazones. The class of compounds includes compounds that are primarily PPARxcex1 agonists and compounds that are mixed PPARxcex1/xcex3 agonists. These compounds are useful in the treatment, control and/or prevention of diabetes, hyperglycemia, mixed or diabetic dyslipidemia, and other lipid disorders (including isolated hypercholesterolemia as manifested by elevations in LDL-C and/or non-HDL-C and/or hyperapoBliproteinemia, hypertriglyceridemia and/or increase in triglyceride-rich-lipoproteins, or low HDL cholesterol concentrations), atherosclerosis, obesity, vascular restenosis, inflammatory conditions, neoplastic conditions, and other PPARxcex1 and/or xcex3 mediated diseases, disorders and conditions.
The present invention provides compounds having the structure of Formula I, including pharmaceutically acceptable salts and prodrugs of these compounds: 
In the compounds of Formula I:
R1 and R2 are each independently selected from the group consisting of H, F, C1-5 alkyl, C2-5 alkenyl, and C2-5 alkynyl, wherein said alkyl, alkenyl, and alkynyl may be linear or branched and are optionally substituted with 1-3 halogen atoms; or optionally R1 and R2 together form a C3-6 cycloalkyl;
R3 and R4 are each independently selected from the group consisting of C1-C5 alkyl, C2-5 alkenyl, C2-5 alkynyl, and chlorine, provided that R3 and R4 are not both chlorine, wherein said alkyl, alkenyl, and alkynyl groups may be linear or branched and are optionally substituted with 1-5 fluorine atoms;
X is N or CR;
Y is O, S, or NR;
Z is O or S;
Each R group is selected from the group consisting of H, C1-5 alkyl, C2-5 alkenyl, and C2-5 alkynyl, wherein said alkyl, alkenyl, and alkynyl may be linear or branched and are optionally substituted with 1-5 fluorine atoms and/or one xe2x80x94OC1-3 alkyl, said xe2x80x94OC1-3 alkyl being optionally substituted with 1-7 fluorine atoms; and
R5 is selected from the group consisting of H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C6-10 Aryl, xe2x80x94OC1-6 alkyl, xe2x80x94OC2-6 alkenyl, xe2x80x94OC2-6 alkynyl, xe2x80x94OC6-10 Aryl, C3-6 Cycloalkyl, 5-6-membered Heterocyclyl, 5-6-membered Heteroaryl, xe2x80x94OC3-6 Cycloalkyl, xe2x80x94O 5-6-membered Heterocyclyl, xe2x80x94O 5-6 membered Heteroaryl, and a C1-4 alkyl group which comprises at a position interrupting the chain or at the end of the chain a group selected from C6-10 Aryl, C3-6 Cycloalkyl, 5-6-membered Heterocyclyl, and 5-6-membered Heteroaryl, wherein each of said alkyl, alkenyl, alkynyl, xe2x80x94Oalkyl, xe2x80x94Oalkenyl, and xe2x80x94Oalkynyl is linear or branched and is optionally substituted with 1-5 fluorine atoms and/or one xe2x80x94OCH3 or xe2x80x94OCF3 group, and each of said Aryl, Cycloalkyl, Heteroaryl, Heterocyclyl, xe2x80x94OAryl, xe2x80x94OCycloalkyl, xe2x80x94OHeteroaryl, and xe2x80x94OHeterocyclyl groups is optionally substituted with 1-7 halogen atoms and/or one xe2x80x94OCH3 or xe2x80x94OCF3 group.
These compounds are effective in lowering glucose, lipids, and insulin in diabetic animals. The compounds are expected to be efficacious in the treatment, control and/or prevention of non-insulin dependent diabetes mellitus (NIDDM) in humans and in the treatment, control, and/or prevention of conditions associated with NIDDM, including hyperlipidemia, dyslipidemia, obesity, hypercholesterolemia, hypertrigyceridemia, atherosclerosis, vascular restenosis, inflammatory conditions, neoplastic conditions, and other PPARxcex1 and/or xcex3 mediated diseases, disorders and conditions.
The invention has numerous embodiments. Several subsets of compounds having different heterocyclic rings are included, as follows:
Compounds of Formula I, in which X is N and Y is O;
Compounds of Formula I, in which X is N and Y is S;
Compounds of Formula I, in which X is N and Y is NR;
Compounds of Formula I, in which X is CR and Y is O;
Compounds of Formula I, in which X is CR and Y is S; and
Compounds of Formula I, in which X is CR and Y is NR.
In further subsets of the compounds of Formula I described above, in which the compounds of Formula I have different heterocycles fused to the aromatic ring (i.e. different values of X and Y), R5 is selected from the group consisting of H, C1-5 alkyl, C2-5 alkenyl, C2-5 alkynyl, OC1-5 alkyl, OC2-5 alkenyl, OC2-5 alkynyl, and phenyl; in these compounds, the alkyl, alkenyl, alkynyl, xe2x80x94Oalkyl, xe2x80x94Oalkenyl, and xe2x80x94Oalkynyl are optionally substituted with 1-5 fluorine atoms, and phenyl is optionally substituted with 1-5 halogens. In a preferred subset, R5 is selected from the group consisting of H, C1-5 alkyl, C2-5 alkenyl, C2-5 alkynyl, OC1-5 alkyl, OC2-5 alkenyl, and OC2-5 alkynyl, where alkyl, alkenyl, alkynyl, xe2x80x94Oalkyl, xe2x80x94Oalkenyl, and xe2x80x94Oalkynyl are optionally substituted with 1-5 fluorine atoms.
In preferred compounds, R1 and R2 are each H or C1-3 alkyl, and the number of carbon atoms in R1 and R2 together is 0-5.
In preferred embodiments, R3 and R4 are each independently C1-5 alkyl. In additional preferred embodiments, one of R3 and R4 is C2-5 alkyl, and the other of R3 and R4 is C1-5 alkyl. In another preferred embodiment, both R3 and R4 are C2-5 alkyl. In other preferred compounds, one of R3 and R4 is C1 or C1-5 alkyl, and the other of R3 and R4 is C2-5 alkyl. In general, the alkyl groups are linear or branched. In the most preferred compounds R3 and R4 are linear when they are alkyl.
In preferred compounds, R5 is selected from C1-5 alkyl and xe2x80x94OC1-5 alkyl, where the alkyl and xe2x80x94Oalkyl are optionally substituted with 1-5 fluorine atoms.
In preferred embodiments, Z is O.
In preferred embodiments, X is N and Y is O, so that the compounds are benzisoxazoles.
In highly preferred embodiments of the groups of compounds above, R5 is C1-3 alkyl, xe2x80x94OC1-3 alkyl, CF3, C2F5, xe2x80x94OCF3 or xe2x80x94OC2F5; and R3 and R4 are each n-propyl
Specific examples of compounds of this invention are provided as Examples 1-29.
The invention further includes pharmaceutical compositions comprising any of the compounds described above and a pharmaceutically acceptable carrier.
The compounds as defined above are useful in the following methods of treating, controlling, and preventing diseases, as well as other diseases not listed below:
(1) a method for treating, controlling or preventing diabetes mellitus, and particularly non-insulin dependent diabetes mellitus, in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(2) a method for treating, controlling, or preventing hyperglycemia in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(3) a method for treating, controlling, or preventing lipid disorders, hyperlipidemia, or low HDL in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(4) a method for treating, controlling, or preventing obesity in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(5) a method for treating, controlling, or preventing hypercholesterolemia in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(6) a method for treating, controlling, or preventing hypertriglyceridemia in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(7) a method for treating, controlling, or preventing dyslipidemia, including low HDL cholesterol, in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I;
(8) a method for treating, controlling, or preventing atherosclerosis in a mammalian patient in need of such treatment which comprises administering to the patient a therapeutically effective amount of a compound of Formula I. It is understood that the sequellae of atherosclerosis (angina, claudication, heart attack, stroke, etc.) are thereby treated.
xe2x80x9cAcxe2x80x9d is acetyl, which is CH3C(O)xe2x80x94.
xe2x80x9cAlkylxe2x80x9d, as well as other groups having the prefix xe2x80x9calkxe2x80x9d, such as alkoxy or alkanoyl, means carbon chains which may be linear or branched or combinations thereof, unless the carbon chain is defined otherwise. Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec- and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, and the like.
xe2x80x9cAlkenylxe2x80x9d means carbon chains which contain at least one carbonxe2x80x94carbon double bond, and which may be linear or branched or combinations thereof. Examples of alkenyl include vinyl, allyl, isopropenyl, pentenyl, hexenyl, heptenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl, and the like.
xe2x80x9cAlkynylxe2x80x9d means carbon chains which contain at least one carbon-carbon triple bond, and which may be linear or branched or combinations thereof. Examples of alkynyl include ethynyl, propargyl, 3-methyl-1-pentynyl, 2-heptynyl and the like.
xe2x80x9cCycloalkylxe2x80x9d means mono- or bicyclic saturated carbocyclic rings, each having from 3 to 10 carbon atoms. The term also includes a monocyclic ring fused to an aryl group in which the point of attachment is on the non-aromatic portion. Examples of cycloalkyl include cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.
xe2x80x9cArylxe2x80x9d (and xe2x80x9carylenexe2x80x9d) means mono- or bicyclic aromatic rings containing only carbon ring atoms. The term also includes an aryl group fused to a monocyclic cycloalkyl or monocyclic heterocyclic group in which the point(s) of attachment is on the aromatic portion. The preferred aryl is phenyl. xe2x80x9cHeterocyclexe2x80x9d and xe2x80x9cheterocyclicxe2x80x9d means a fully or partially saturated monocyclic, bicyclic or tricyclic ring containing at least one heteroatom selected from N, S and O, each of said rings having from 3 to 10 atoms. Examples of aryl include phenyl, naphthyl, indanyl, indenyl, and tetrahydronaphthyl. Examples of aryl fused to heterocyclic groups include 2,3-dihydrobenzofuranyl, benzopyranyl, 1,4-benzodioxanyl, and the like. Examples of heterocycles include tetrahydrofuran, piperazine, and morpholine.
xe2x80x9cHeteroarylxe2x80x9d (and heteroarylene) means a mono-, bi- or tricyclic aromatic ring containing at least one ring heteroatom selected from N, O and S (including SO and SO2), with each ring containing 5 to 6 atoms. Examples of heteroaryl include pyrrolyl, isoxazolyl, isothiazolyl, pyrazolyl, pyridyl, oxazolyl, oxadiazolyl, thiadiazolyl, thiazolyl, imidazolyl, triazolyl, tetrazolyl, furanyl, triazinyl, thienyl, pyrimidyl, pyridazinyl, pyrazinyl, benzisoxazolyl, benzoxazolyl, benzothiazolyl, benzimidazolyl, benzofuranyl, benzothiophenyl (including S-oxide and dioxide), furo(2,3-b)pyridyl, quinolyl, indolyl, isoquinolyl, dibenzofuran and the like.
xe2x80x9cHalogenxe2x80x9d includes fluorine, chlorine, bromine and iodine.
The term xe2x80x9ccomposition,xe2x80x9d as in pharmaceutical composition, is intended to encompass a product comprising the active ingredient(s), and the inert ingredient(s) that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients. Accordingly, the pharmaceutical compositions of the present invention encompass any composition made by admixing a compound of the present invention and a pharmaceutically acceptable carrier.
Compounds of Formula I may contain one or more asymmetric centers and can thus occur as racemates and racemic mixtures, single enantiomers, diastereomeric mixtures and individual diastereomers. The present invention is meant to comprehend all such isomeric forms of the compounds of Formula I.
Some of the compounds described herein contain olefinic double bonds, and unless specified otherwise, are meant to include both E and Z geometric isomers.
Some of the compounds described herein may exist with different points of attachment of hydrogen, referred to as tautomers. Such an example may be a ketone and its enol form, known as keto-enol tautomers. The individual tautomers as well as mixtures thereof are encompassed with compounds of Formula I.
Compounds of the Formula I may be separated into diastereoisomeric pairs of enantiomers by, for example, fractional crystallization from a suitable solvent, for example methanol or ethyl acetate or a mixture thereof. The pair of enantiomers thus obtained may be separated into individual stereoisomers by conventional means, for example by the use of an optically active acid or base as a resolving agent.
Alternatively, any enantiomer of a compound of the general Formula I or Ia may be obtained by stereospecific synthesis using optically pure starting materials or reagents of known configuration.
The term xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids including inorganic or organic bases and inorganic or organic acids. Salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like. Particularly preferred are the ammonium, calcium, magnesium, potassium, and sodium salts. Salts in the solid form may exist in more than one crystal structure, and may also be in the form of hydrates. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, and basic ion exchange resins, such as arginine, betaine, caffeine, choline, N,Nxe2x80x2-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethyl-morpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine, and the like.
When the compound of the present invention is basic, salts may be prepared from pharmaceutically acceptable non-toxic acids, including inorganic and organic acids. Such acids include acetic, benzenesulfonic, benzoic, camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the like. Particularly preferred are citric, hydrobromic, hydrochloric, maleic, phosphoric, sulfuric, and tartaric acids.
It will be understood that, as used herein, references to the compounds of Formula I are meant to also include the pharmaceutically acceptable salts.
Metabolites of the compounds of this invention that are therapeutically active also are within the scope of the claimed parent compound. Prodrugs, which are compounds that are converted to the claimed compounds as they are being administered to a patient or after they have been administered to a patient, are also within the scope of the claimed active compound. A non-limiting example of a prodrug of the carboxylic acids of this invention would be an ester of the carboxylic acid group, for example a C1 to C6 ester, which may be linear or branched, or an ester which has functionality that makes it more easily hydrolyzed after administration to a patient.
Prodrugs of this class of compounds may be described as compounds having the Formula Ia: 
wherein R6 is a group that is easily removed under physiological conditions during or after administration to a mammalian patient to yield a compound having Formula I, or the carboxylate anion thereof (in solution), or a pharmaceutically acceptable salt thereof, where R1, R2, R3, R4, R5, X, Y, Z, and R are as defined above for compounds having Formula I.
Examples of prodrugs of Formula Ia include compounds in which R6 is selected from the group consisting of xe2x80x94OR7, xe2x80x94OCH2OR7, xe2x80x94OCH(CH3)OR7, xe2x80x94OCH2OC(O)R7, xe2x80x94OCH(CH3)OC(O)R7, xe2x80x94OCH2OC(O)OR7, xe2x80x94OCH(CH3)OC(O)OR7, xe2x80x94NR8R8, and xe2x80x94ONR8R8, where each R7 is independently selected from C1-6 alkyl optionally substituted with one or two groups selected from xe2x80x94CO2H, xe2x80x94CONH2, xe2x80x94NH2, xe2x80x94OH, xe2x80x94OAc, NHAc, and phenyl; and wherein each R8 is independently selected from H and R7. Compounds having Formula Ia, where R6 has the chemical structure described above, are described as prodrugs. However, regardless of whether they are active as prodrugs, yielding compounds or salts of Formula I, or whether they have a different means of exhibiting pharmaceutical activity, the compounds of Formula Ia are included in this invention. Such compounds are claimed herein, regardless of the mechanism leading to their activity.
The description of utility, pharmaceutical compositions, combination therapies, administration, dosage, and the like are all described in terms of compounds of Formula I. These descriptions of utility, etc. also apply to compounds of Formula Ia.
Compounds of the present invention are potent agonists of varioius peroxisome proliferator activator receptor subtypes, particularly PPARxcex1 and/or PPARxcex3. Compounds of the present invention may be selective agonists of one receptor subtype, e.g. PPARxcex3 or PPARxcex1 agonists, or they may be agonists of more than one receptor subtypes, e.g. dual PPARxcex1/xcex3 agonists. Compounds of the present invention are useful in treating, controlling or preventing diseases, disorders or conditions, wherein the treatment is mediated by the activation of an individual PPAR subtype (xcex1 or xcex3), or a combination of PPAR subtypes (e.g. xcex1/xcex3). Thus one aspect of the present invention provides a method for the treatment, control or prevention of such diseases, disorders, or conditions in a mammal which comprises administering to such mammal a therapeutically effective amount of a compound of Formula I. The diseases, disorders or conditions for which compounds of the present invention are useful in treating, controlling or preventing include, but are not limited to, (1) diabetes mellitus, and especially non-insulin dependent diabetes mellitus (NIDDM), (2) hyperglycemia, (3) low glucose tolerance, (4) insulin resistance, (5) obesity, (6) lipid disorders, (7) dyslipidemia, (8) hyperlipidemia, (9) hypertriglyceridemia, (10) hypercholesterolemia, (11) low HDL levels, (12) high LDL levels, (13) atherosclerosis and its sequelae, (14) vascular restenosis, (15) irritable bowel syndrome, (16) inflamatory bowel disease, including Crohn""s disease and ulcerative colitis, (17) other inflammatory conditions, (18) pancreatitis, (19) abdominal obesity, (20) neurodegenerative disease, (21) retinopathy, (22) neoplastic conditions, (23) adipose cell tumors, (24) adipose cell carcinomas, such as liposarcoma, (25) prostate cancer and other cancers, including gastric, breast, bladder and colon cancers, (26) angiogenesis, (27) Alzheimer""s disease, (28) psoriasis, (29)high blood pressure, (30) Syndrome X, (31) ovarian hyperandrogenism (polycystic ovarian syndrome), and other disorders where insulin resistance is a component.
Another aspect of the invention provides a method for the treatment, control, or prevention of hypercholesterolemia, atherosclerosis, low HDL levels, high LDL levels, hyperlipidemia, hypertriglyceridemia, and/or dyslipidemia, which comprises administering to a mammal in need of such treatment a therapeutically effective amount of an agonist of PPARxcex1 and/or PPARxcex3 or a PPARxcex1/xcex3 dual agonist. The PPAR agonist may be used alone or advantageously may be administered with a cholesterol biosynthesis inhibitor, particularly an HMG-CoA reductase inhibitor such as lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, rivastatin, itavastatin, or ZD-4522. The PPAR agonist may also be used advantageously in combination with other lipid lowering drugs such as cholesterol absorption inhibitors (for example stanol esters, sterol glycosides such as tiqueside, and azetidinones such as ezetimibe), ACAT inhibitors (such as avasimibe), and with niacin, bile acid sequestrants, microsomal triglyceride transport inhibitors, and bile acid reuptake inhibitors. These combination treatments may also be effective for the treatment, control or prevention of one or more related conditions selected from the group consisting of hypercholesterolemia, atherosclerosis, hyperlipidemia, hypertriglyceridemia, dyslipidemia, high LDL, and low HDL.
Another aspect of the invention provides a method of treating inflammatory conditions, including inflammatory bowel disease, Crohn""s disease, and ulcerative colitis by administering an effective amount of a PPAR agonist, which may be a PPARxcex1 agonist, a PPARxcex3 agonist, or a PPARxcex1/xcex3 dual agonist. Additional inflammatory diseases that may be treated with the instant invention include gout, rheumatoid arthritis, osteoarthritis, multiple sclerosis, asthma, ARDS, psoriasis, vasculitis, ischemia/reperfusion injury, frostbite, and related diseases.
Any suitable route of administration may be employed for providing a mammal, especially a human, with an effective dose of a compound of the present invention. For example, oral, rectal, topical, parenteral, ocular, pulmonary, nasal, and the like may be employed. Dosage forms include tablets, troches, dispersions, suspensions, solutions, capsules, creams, ointments, aerosols, and the like. Preferably compounds of Formula I are administered orally.
The effective dosage of active ingredient employed may vary depending on the particular compound employed, the mode of administration, the condition being treated and the severity of the condition being treated. Such dosage may be ascertained readily by a person skilled in the art.
When treating or preventing diabetes mellitus and/or hyperglycemia or hypertriglyceridemia or other diseases for which compounds of Formula I are indicated, generally satisfactory results are obtained when the compounds of the present invention are administered at a daily dosage of from about 0.1 milligram to about 100 milligram per kilogram of animal body weight, preferably given as a single daily dose or in divided doses two to six times a day, or in sustained release form. For most large mammals, the total daily dosage is from about 1.0 milligrams to about 1000 milligrams, preferably from about 1 milligrams to about 50 milligrams. In the case of a 70 kg adult human, the total daily dose will generally be from about 7 milligrams to about 350 milligrams. This dosage regimen may be adjusted to provide the optimal therapeutic response.
Another aspect of the present invention provides pharmaceutical compositions which comprise a compound of Formula I and a pharmaceutically acceptable carrier. The pharmaceutical compositions of the present invention comprise a compound of Formula I or a pharmaceutically acceptable salt or prodrug thereof as an active ingredient, as well as a pharmaceutically acceptable carrier and optionally other therapeutic ingredients. The term xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids including inorganic bases or acids and organic bases or acids.
The compositions include compositions suitable for oral, rectal, topical, parenteral (including subcutaneous, intramuscular, and intravenous), ocular (ophthalmic), pulmonary (nasal or buccal inhalation), or nasal administration, although the most suitable route in any given case will depend on the nature and severity of the conditions being treated and on the nature of the active ingredient. They may be conveniently presented in unit dosage form and prepared by any of the methods well-known in the art of pharmacy.
In practical use, the compounds of Formula I can be combined as the active ingredient in intimate admixture with a pharmaceutical carrier according to conventional pharmaceutical compounding techniques. The carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral (including intravenous). In preparing the compositions for oral dosage form, any of the usual pharmaceutical media may be employed, such as, for example, water, glycols, oils, alcohols, flavoring agents, preservatives, coloring agents and the like in the case of oral liquid preparations, such as, for example, suspensions, elixirs and solutions; or carriers such as starches, sugars, microcrystalline cellulose, diluents, granulating agents, lubricants, binders, disintegrating agents and the like in the case of oral solid preparations such as, for example, powders, hard and soft capsules and tablets, with the solid oral preparations being preferred over the liquid preparations.
Because of their ease of administration, tablets and capsules represent the most advantageous oral dosage unit form in which case solid pharmaceutical carriers are obviously employed. If desired, tablets may be coated by standard aqueous or nonaqueous techniques. Such compositions and preparations should contain at least 0.1 percent of active compound. The percentage of active compound in these compositions may, of course, be varied and may conveniently be between about 2 percent to about 60 percent of the weight of the unit. The amount of active compound in such therapeutically useful compositions is such that an effective dosage will be obtained. The active compounds can also be administered intranasally as, for example, liquid drops or spray.
The tablets, pills, capsules, and the like may also contain a binder such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, lactose or saccharin. When a dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier such as a fatty oil.
Various other materials may be present as coatings or to modify the physical form of the dosage unit. For instance, tablets may be coated with shellac, sugar or both. A syrup or elixir may contain, in addition to the active ingredient, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye and a flavoring such as cherry or orange flavor.
Compounds of formula I may also be administered parenterally. Solutions or suspensions of these active compounds can be prepared in water suitably mixed with a surfactant such as hydroxy-propylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols and mixtures thereof in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.
The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g. glycerol, propylene glycol and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils.
Compounds of Formula I may be used in combination with other drugs that may also be useful in the treatment, prevention, suppression or amelioration of the diseases or conditions for which compounds of Formula I are useful. Such other drugs may be administered, by a route and in an amount commonly used therefor, contemporaneously or sequentially with a compound of Formula I. When a compound of Formula I is used contemporaneously with one or more other drugs, a pharmaceutical composition in unit dosage form containing such other drugs and the compound of Formula I is preferred. However, the combination therapy also includes therapies in which the compound of Formula I and one or more other drugs are administered on different overlapping schedules. It is also contemplated that when used in combination with one or more other active ingredients, the compound of the present invention and the other active ingredients may be used in lower doses than when each is used singly. Accordingly, the pharmaceutical compositions of the present invention include those that contain one or more other active ingredients, in addition to a compound of Formula I.
Examples of other active ingredients that may be administered in combination with a compound of Formula I, and either administered separately or in the same pharmaceutical composition, include, but are not limited to:
(a) insulin sensitizers including (i) PPARxcex3 agonists such as the glitazones (e.g. troglitazone, pioglitazone, englitazone, MCC-555, rosiglitazone, and the like), and compounds disclosed in WO97/27857, 97/28115, 97/28137 and 97/27847; (ii) biguanides such as metformin and phenformin; (iii) protein tyrosine phosphatase-1B (PTP-1B) inhibitors, and (iv) dipeptidyl peptidase IV (DP-IV) inhibitors;
(b) insulin or insulin mimetics;
(c) sulfonylureas such as tolbutamide and glipizide, or related materials;
(d) xcex1-glucosidase inhibitors (such as acarbose);
(e) cholesterol lowering agents such as (i) HMG-CoA reductase inhibitors (lovastatin, simvastatin, pravastatin, fluvastatin, atorvastatin, rivastatin, itavastatin, ZD-4522 and other statins), (ii) sequestrants (cholestyramine, colestipol, and dialkylaminoalkyl derivatives of a cross-linked dextran), (iii) nicotinyl alcohol, nicotinic acid or a salt thereof, (iv) PPARxcex1 agonists such as fenofibric acid derivatives (gemfibrozil, clofibrate, fenofibrate and benzafibrate), (v) PPARxcex1/xcex3 dual agonists, such as KRP-297, (vi) inhibitors of cholesterol absorption, such as for example beta-sitosterol, (vii) acyl CoA:cholesterol acyltransferase inhibitors, such as for example avasimibe, and (viii) anti-oxidants, such as probucol;
(f) PPARxcex4 agonists such as those disclosed in WO97/28149;
(g) antiobesity compounds such as fenfluramine, dexfenfluramine, phentiramine, sulbitramine, orlistat, neuropeptide Y5 inhibitors, and xcex23 adrenergic receptor agonists;
(h) an ileal bile acid transporter inhibitor; and
(i) agents intended for use in inflammatory conditions such as aspirin, non-steroidal anti-inflammatory drugs, glucocorticoids, azulfidine, and cyclooxygenase 2 selective inhibitors.
The above combinations include combinations of a compound of the present invention not only with one other active compound, but also with two or more other active compounds. Non-limiting examples include combinations of compounds having Formula I with two or more active compounds selected from biguanides, sulfonylureas, HMG-CoA reductase inhibitors, other PPAR agonists, PTP-1B inhibitors, DP-IV inhibitors, and anti-obesity compounds.
A) PPAR Binding Assays
For preparation of recombinant human PPARxcex3, PPARxcex4, and PPARxcex1: Human PPARxcex32, human PPARxcex4 and human PPARxcex1 were expressed as gst-fusion proteins in E. coli. The full length human cDNA for PPARxcex32 was subcloned into the pGEX-2T expression vector (Pharmacia). The full length human cDNAs for PPARxcex4 and PPARxcex1 were subcloned into the pGEX-KT expression vector (Pharmacia). E. coli containing the respective plasmids were propagated, induced, and harvested by centrifugation. The resuspended pellet was broken in a French press and debris was removed by centrifugation at 12,000xc3x97g. Recombinant human PPAR receptors were purified by affinity chromatography on glutathione sepharose. After application to the column, and one wash, receptor was eluted with glutathione. Glycerol (10%) was added to stabilize the receptor and aliquots were stored at xe2x88x9280xc2x0 C. For binding to PPARxcex3, an aliquot of receptor was incubated in TEGM (10 mM Tris, pH 7.2, 1 mM EDTA, 10% glycerol, 7 xcexcL/100 mL xcex2-mercaptoethanol, 10 mM Na molybdate, 1 mM dithiothreitol, 5 xcexcg/mL aprotinin, 2 xcexcg/mL leupeptin, 2 xcexcg/mL benzamidine and 0.5 mM PMSF) containing 0.1% non-fat dry milk and 10 nM [3H2] AD5075, (21 Ci/mmole), xc2x1 test compound as described in Berger et al (Novel peroxisome proliferator-activated receptor (PPARxcex3) and PPARxcex4 ligands produce distinct biological effects. J. Biol. Chem. (1999), 274: 6718-6725. Assays were incubated for xcx9c16 hr at 4xc2x0 C. in a final volume of 150 xcexcL. Unbound ligand was removed by incubation with 100 xcexcL dextran/gelatin-coated charcoal, on ice, for xcx9c10 min. After centrifugation at 3000 rpm for 10 min at 4xc2x0 C., 50 xcexcL of the supernatant fraction was counted in a Topcount.
For binding to PPARxcex4, an aliquot of receptor was incubated in TEGM (10 mM Tris, pH 7.2, 1 mM EDTA, 10% glycerol, 7 xcexcL/100 mL xcex2-mercaptoethanol, 10 mM Na molybdate, 1 mM dithiothreitol, 5 xcexcg/mL aprotinin, 2 xcexcg/mL leupeptin, 2 xcexcg/mL benzamide and 0.5 mM PMSF) containing 0.1% non-fat dry milk and 2.5 nM [3H2]-Comp""d A, (17 Ci/mmole), xc2x1 test compound as described in Berger et al (Novel peroxisome proliferator-activated receptorxcex3 (PPARxcex3) and PPARxcex4 ligands produce distinct biological effects.1999 J Biol Chem 274: 6718-6725). (Comp""d A is 3-chloro-4-(3-(7-propyl-3-trifluoromethyl-6-benz-[4,5]-isoxazoloxy)prophylthio)phenylacetic acid, Ex. 20 in WO 97/28137). Assays were incubated for xcx9c16 hr at 4xc2x0 C. in a final volume of 150 xcexcL. Unbound ligand was removed by incubation with 100 xcexcL dextran/gelatin-coated charcoal, on ice, for xcx9c10 min. After centrifugation at 3000 rpm for 10 min at 4xc2x0 C., 50 xcexcL of the supernatant fraction was counted in a Topcount.
For binding to PPARxcex1, an aliquot of receptor was incubated in TEGM (10 mM Tris, pH 7.2, 1 mM EDTA, 10% glycerol, 7 xcexcL/100 mL xcex2-mercaptoethanol, 10 mM Na molybdate, 1 mM dithiothreitol, 5 xcexcg/mL aprotinin, 2 xcexcg/mL leupeptin, 2 xcexcg/mL benzamide and 0.5 mM PMSF) containing 0.1% non-fat dry milk and 5.0 nM [3H2]-Comp""d B, (34 Ci/mmole), xc2x1 test compound. (Comp""d B is (3-(4-(3-phenyl-7 -propyl-6-benz-[4,5]-isoxazoloxy)butyloxy))phenylacetic acid, Ex.62 in WO 97/28137). Assays were incubated for xcx9c16 hr at 4xc2x0 C. in a final volume of 150 xcexcL. Unbound ligand was removed by incubation with 100 xcexcL dextran/gelatin-coated charcoal, on ice, for xcx9c10 min. After centrifugation at 3000 rpm for 10 min at 4xc2x0 C., 50 xcexcL of the supernatant fraction was counted in a Topcount.
B). Gal-4 hPPAR Transactivation Assays
The chimeric receptor expression constructs, pcDNA3-hPPARxcex3/GAL4, pcDNA3-hPPARxcex4/GAL4, pcDNA3-hPPARxcex1/GAL4 were prepared by inserting the yeast GAL4 transcription factor DBD adjacent to the ligand binding domains (LBDs) of hPPARxcex3, hPPARxcex4, hPPARxcex1, respectively. The reporter construct, pUAS(5xc3x97)-tk-luc was generated by inserting 5 copies of the GAL4 response element upstream of the herpes virus minimal thymidine kinase promoter and the luciferase reporter gene. pCMV-lacZ contains the galactosidase Z gene under the regulation of the cytomegalovirus promoter. COS-1 cells were seeded at 12xc3x97103 cells/well in 96 well cell culture plates in high glucose Dulbecco""s modified Eagle medium (DMEM) containing 10% charcoal stripped fetal calf serum (Gemini Bio-Products, Calabasas, Calif.), nonessential amino acids, 100 units/ml Penicillin G and 100 mg/ml Streptomycin sulfate at 37 xc2x0 C. in a humidified atmosphere of 10% CO2. After 24 h, transfections were performed with Lipofectamine (GIBCO BRL, Gaithersburg, Md.) according to the instructions of the manufacturer. Briefly, transfection mixes for each well contained 0.48 xcexcl of Lipofectamine, 0.00075 xcexcg of pcDNA3-PPAR/GAL4 expression vector, 0.045 xcexcg of pUAS(5xc3x97)-tk-luc reporter vector and 0.0002 xcexcg of pCMV-lacZ as an internal control for transactivation efficiency. Cells were incubated in the transfection mixture for 5 h at 37xc2x0 C. in an atmosphere of 10% CO2. The cells were then incubated for xcx9c48 h in fresh high glucose DMEM containing 5% charcoal stripped fetal calf serum, nonessential amino acids, 100 units/ml Penicillin G and 100 mg/ml Streptomycin sulfate xc2x1 increasing concentrations of test compound. Since the compounds were solubilized in DMSO, control cells were incubated with equivalent concentrations of DMSO; final DMSO concentrations were xe2x89xa60.1%, a concentration which was shown not to effect transactivation activity. Cell lysates were produced using Reporter Lysis Buffer (Promega, Madison, Wis.) according to the manufacturer""s instructions. Luciferase activity in cell extracts was determined using Luciferase Assay Buffer (Promega, Madison, Wis.) in an ML3000 luminometer (Dynatech Laboratories, Chantilly, Va.). xcex2-galactosidase activity was determined using xcex2-D-galactopyranoside (Calbiochem, San Diego, Calif.).
C. In Vivo Studies
Male db/db mice (10-11 week old C57B1/KFJ, Jackson Labs, Bar Harbor, Me.) were housed 5/cage and allowed ad lib. access to ground Purina rodent chow and water. The animals, and their food, were weighed every 2 days and were dosed daily by gavage with vehicle (0.5% carboxymethylcellulose) xc2x1 test compound at the indicated dose. Drug suspensions were prepared daily. Plasma glucose, and triglyceride concentrations were determined from blood obtained by tail bleeds at 3-5 day intervals during the study period. Glucose, and triglyceride, determinations were performed on a Boehringer Mannheim Hitachi 911 automatic analyzer (Boehringer Mannheim, Indianapolis, Ind.) using heparinized plasma diluted 1:6 (v/v) with normal saline. Lean animals were age-matched heterozygous mice maintained in the same manner.